Question

3) find the focus & length of latus rectum of parabola
yta 20x (with formula)
​

Answer 1

Answer:

y

2

=20x

⇒y

2

=4(s)x

∴ From general eqn of parabola y

2

=4ax,

we get, a=5

Coordinates of focus→(a,0)

=(5,0)

Equation of directrix ⇒x=−a

⇒x=−5

⇒x+5=0

Length of latus rectum →4a

4×5=20

Coordinates of end points of

latus rectum are (a,2a)&(a,−2a)

→(5,10)&(5,−10) Ans.